The number of solutions of the congruence in the box is estimated from below in the best possible way, provided for all i,j either or or .
@article{bwmeta1.element.bwnjournal-article-doi-10_4064-cm106-2-8,
author = {A. Schinzel and M. Zakarczemny},
title = {On a linear homogeneous congruence},
journal = {Colloquium Mathematicae},
volume = {106},
year = {2006},
pages = {283-292},
zbl = {1153.11017},
language = {en},
url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-cm106-2-8}
}
A. Schinzel; M. Zakarczemny. On a linear homogeneous congruence. Colloquium Mathematicae, Tome 106 (2006) pp. 283-292. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-cm106-2-8/